Adaptation of Silvicultural Practices to Climate Change

In 2023, the Forest Research Branch of Quebec’s Ministry of Natural Resources and Forests (MNRF) began testing strategies to adapt silviculture practices to climate change in three areas of Quebec. They’re doing this because the forests in Quebec are facing challenges like droughts, longer growing seasons, higher temperatures, more freeze-thaw events, and changes in peak-flows.

The forestry sector is important because it provides habitat for animals and plays a key role in the economy. Silviculture is the practice of controlling how forests grow and stay healthy to meet the needs of people and the land. Quebec has two main types of climate zones: temperate with mixed and broadleaf trees, and boreal which is mainly composed of black spruce, jack pine, and balsam fir. Most of Quebec’s forests are public (91%). The forests play a key role in the province’s economy, providing roughly 60,000 jobs, half of which are in the wood products sector, and one-third in the paper industry.

Silviculture is the art and science of controlling the establishment, growth, composition, health, and quality of forests and woodlands to meet the diverse needs and values of landowners and society on a sustainable basis. With funding through the Government of Quebec’s Plan pour une économie verte 2030, the Forest Research Branch launched three projects that follow the Resistance, Resilience, and Transition framework commonly used in forestry climate change adaptation work. The Resistance Project focuses on making white spruce and jack pine better able to handle water stress caused by drought in the Outaouais region. The Resilience Project in the Chibougamau region looks at using mixed-species plantations to lower the risk of losing forest investments in areas prone to fires. Finally, the Transition Project in the Gaspésie region explores the management of tree species composition through enrichment planting and planting mixed species following partial harvests.

The forestry sector plays an important role in fighting climate change by capturing carbon in the forests and wood products. But climate change is affecting the ability of forests to do this, so it’s crucial to adapt the way we take care of the forests. Without adaptation, mitigation measures will not succeed because they are interconnected. The results of these projects will guide how to care for the forests, ensuring their sustainability for the benefit of everyone in Quebec.

Understanding and Assessing Impacts

Climate change impacts on the forest ecosystem are diverse, and Quebec is already observing changes in the form of rising temperatures that are affecting the distribution and health of tree species, increased rainfall leading to soil erosion and flooding, droughts causing water stress and damage to trees, more frequent and severe forest fires due to prolonged dry periods, and more frequent freeze-thaw events. The Outaouais region which contains parts of the Boreal Forest, has experienced more drought events in the spring, and in the fall, which leads to an increased risk to trees.

To identify climate risks to each region, an expert team from the MNRF conducted a vulnerability assessment, which combined climate data models with habitat models, and a literature review to support findings. In collaboration with Ouranos, the team used data from Climate Portraits – a regional portal of climate-related information that offers spatialized information across Quebec to visualize climate normals, historic observations and the changes projected by climate models. The portal uses Climate Model Intercomparison Project Phase 5 and Phase 6 (CMIP5/CMIP6) simulations for the 2050 time period, under Representative Concentration Pathways (RCP) 4.5 and 8.5.

The study found that by 2050, there could be more droughts, a longer growing season, higher average temperatures, more freeze-thaw events, and higher peak-flows. These changes can affect how the forest works, like how much it produces, what trees grow there, how much gets burned in fires, how often new trees grow, and how bugs and invasive plants spread. The roads and infrastructure in the forests might also be affected. The study also predicts that it’s going to get hotter, but the amount of rain will probably stay the same. This increase in heat waves is significant for water and the types of trees that can survive. Even modest climate change will lead to major changes in forests.

Identifying Actions

The research program is a team effort involving different partners and groups, including the University of Montreal, Université du Québec à Chicoutimi, Université du Québec à Rimouski, Université du Québec en Abitibi-Témiscamingue, and Quebec’s Ministry of Natural Resources and Forests (MNRF). They’re working together to figure out how to make sure Quebec’s forests can handle changes in the environment. The project follows a plan called Resistance, Resilience, Transition, which is a way of adapting how we take care of the forests. The goal of the program is to come up with different ways for forest managers to deal with climate change while still reaching their management goals. They want to make sure the ecosystems can survive and adapt to changes. ‘Resistance’ means making the ecosystems stronger against change, either by keeping them the same or giving them time to adapt. ‘Resilience’ is about how well the ecosystems can handle problems and go back to a similar state. ‘Transition’ is about changing the ecosystem by adjusting the types of species to better deal with the new climate.

In 2020, workshops were held in three test areas – Gaspésie (Iles de la Madeleine), Nord-du-Québec, and Outaouais. The workshops brought researchers together from the Ministry’s research branch, forestry professionals from various ministry directions in Québec City and forestry professionals located in each pilot region. They talked about the risks of climate change in their regions and shared what they’re currently doing to take care of the forests in their areas. Then, they discussed which ways of taking care of the forests might be at risk and came up with options to deal with climate change. The results of these workshops shaped the research program that officially started in 2022.

Implementation

The research team used the results of the vulnerability assessment and discussions at workshops to create and apply one research project in three different regions. They plan to test one adaptation strategy in each region. The first project is focused on improving “Resistance” in the Outaouais region, near Ottawa. This involves using commercial thinning practices to make forest plantations more resilient to water stress from periods of prolonged drought. The main goal is to see how well different thinning intensities can help trees in plantations cope with drought. Two species will be tested: white spruce and jack pine. They will also install various instruments to collect data for a thorough analysis. The white spruce is one of the main tree species planted in Quebec, and this project represents an important step in research on genetic improvement.

The second project, called the “Resilience” initiative, is located near Chibougamau in the Boreal Forest in the northern part of the province. This project explores the concept of using mixed plantings as a tool to reduce the likelihood of losing silvicultural investments, particularly in regions at greater risk of fire. A dedicated doctoral student from Italy has been leading this project since 2023. This project has already begun, with all experimental sites having undergone harvesting in 2022. It was originally intended to do experiments in areas formerly affected by wildfire, but none were accessible at the time. Then unexpectedly, wildfires occurred the following summer in 2023, so the project team decided to do the experiment in these recently burned sites. Ironically, wildfires which are occurring more frequently because of climate change, supported the climate change adaptation objective of this project, which also sheds light on the forest’s regenerative abilities. In the first year, they expect nutrients to wash into the soil. The research will look at how both types of trees involved react to the washout. The research team will test a mix of Jack Pine and Black Spruce, along with Tamarack – a tree species known for its rapid growth.

The third project, based in Gaspésie, will focus on the theme of “Transition.” It will explore the management of trees in both planted areas and natural forests using two strategies: one is enrichment planting, and the other is planting a mix of different tree species. These methods will be carried out in the context of assisted migration, and it will be done after they partially cut down some trees. The project has three main experiments. The first experiment involves migrating Red Oak to new areas and will include testing different sources of seeds very carefully. Implementation is scheduled for 2025 and will be conducted in collaboration with the CERFO, helping to fill gaps in knowledge and practical application. The research team hopes to support this work through their application for a grant from the Natural Sciences and Engineering Research Council of Canada (NSERC). The second experiment is about enrichment planting. It involves carefully introducing a chosen mix of three to four broadleaf species and five conifer species to certain areas. At the same time, the project team will plant a mix of different species, although the specific species to be included will be determined at a later stage. The sites will be prepared in 2024, and planting is scheduled for 2025. This experiment aims to gather insight on how forest ecosystems respond to increased species diversity. The third experiment will test broadleaf and conifer species following clear-cutting. This experiment aims to validate models that predict trees moving north in response to changing climate conditions. The project aims to connect what ‘might happen’ in the forest with what ‘really happens’, helping us understand how forests change because of climate change.

Outcomes and Monitoring Progress

The projects are actively progressing, and silvicultural efforts have commenced in all regions, thanks to the valuable support extended by the MNRF’s Regional Operations Sector. Two projects will receive further assistance from doctoral students during the upcoming fall and winter seasons (2023/2024). Unfortunately, the project team is finding it hard to access seeds to be used for seedling production in the reforestation components of the projects. This is due to a scarcity of available seeds caused by recent extreme weather events. In 2022, Quebec’s MNRF reported that a staggering 11.5 million tree seedlings, designated for Quebec nurseries, silviculture companies, and research initiatives, were destroyed and can be attributed to severe and unpredictable weather events. According to MNRF, an overwhelming 83 per cent of these losses were attributed to severe weather.. Factors such as early fall frosts, little amounts of snow cover, mild winter temperatures, or late spring frosts can all cause damage to seedlings. Despite these challenges, managers of seed and forest plant production at the MRNF are actively collaborating with the research team to ensure the availability of seedlings for establishing plantations.

The research team submits regular progress reports to the Ministère de l’Environnement et de la Lutte contre les changements climatiques, de la Faune et des Parcs (MELCCFP) who is providing financial support through the “Plan pour une économie verte 2030” until 2027. The three projects received a combined total of $2.5 million over five years, with the expectation of funding renewal thereafter. The funding played a significant role in the design of the project. Without it, the scale of the projects would have been smaller and the research team would have sought funding from elsewhere.

Next Steps

The research team intends to eventually expand the projects to other regions of Quebec. Next steps include planning for planting next year and establishing a long-term monitoring plan that spans more than two decades. This in-depth monitoring will provide valuable information on the long-term outcomes of the project and the forest’s response to mixed species plantings in fire-prone areas.

The project team is also developing a separate project proposal that will focus on managing city boundaries for firebreaks, particularly considering recent wildfires. Various experiments in different cities are planned that test hybrid poplars as an alternative to clearcutting to protect existing ecosystems.

Resources

Link to the Full Case Study

Additional Resources: 

Using climate change projections enables better adaptation decisions, as it allows you to better understand how the climate may change. To learn how to choose, access, and understand climate data, visit ClimateData.ca’s Learning Zone.

Visit ClimateData.ca and click “Explore by Variable” for future climate projections related to temperature and precipitation, which can be used to inform adaptation planning.